HPNS Explained with DAN's Dr. Richard Vann

In this DAN Tech Time episode of Pod Diver Radio, host Joe Cocozza sits down with Dr. Richard Vann to break down HPNS—High Pressure Nervous Syndrome—for serious technical divers. They unpack what HPNS actually is, why it's pressure (not helium) driven, and how enzyme distortion at extreme depth leads to tremors, sleep disruption, loss of appetite, and even psychosis on very deep dives. Dr. Vann also explains why HPNS starts to show up around 600 ft / 180 m, why rapid "bounce" dives make tech divers more vulnerable than saturation teams, and how adding narcotic gases like nitrogen or hydrogen can partially counteract HPNS on deep helium dives. If you're planning extreme trimix, dreaming about 500+ ft cave or wreck dives, or just want to understand the real science behind The Abyss, this episode is your deep-physics briefing on HPNS, helium, and ultra-deep decompression strategy.